The invention pertains to container-shaped physical vapor deposition targets, and to methods of forming container-shaped physical vapor deposition targets.
An exemplary sputtering process utilizing a container-shaped physical vapor deposition target is described with reference to FIG. 1. Specifically, FIG. 1 illustrates a sputtering apparatus 10, having a container-shaped physical vapor deposition target 12 incorporated therein. Apparatus 10 further comprises a substrate holder 14 and a substrate 16 provided on holder 14. Substrate 16 can comprise, for example, a semiconductive material wafer. In operation, atoms and/or ions are displaced from an interior region of target 12 and directed toward substrate 16. The displaced materials are illustrated by arrows 18 in the diagram of FIG. 1. A voltage differential or bias can be provided between target 12 and substrate 16, as shown, to draw charged materials from target 12 to substrate 16. The materials displaced from target 12 are deposited on an upper surface of substrate 16 to form a thin film (not shown) on substrate 16. In an exemplary process, target 12 can comprise copper. Copper ions and/or copper atoms can be sputter-deposited from target 12 onto substrate 16 to form a thin film of copper across an upper surface of substrate 16.
Target 12 is one example of a container-shaped physical vapor deposition target. For purposes of interpreting this disclosure and the claims that follow, a container-shaped physical vapor deposition target is defined as a physical vapor deposition target having a closed-ended cavity extending therein, and wherein a predominate feature of the target is the cavity. For instance, the target 12 of FIG. 10 has a closed-ended cavity 20 extending therein (with the closed-end being labeled 22 in FIG. 1), and cavity 20 is a predominate feature of the target.
FIG. 2 shows a bottom-view (relative to the view of FIG. 1) of target 12, and shows a configuration of target 12 wherein the target comprises a circular outer periphery surrounding cavity 20.
It can be difficult to form container-shaped targets, and accordingly it is desired to develop new methodologies for forming container-shaped targets.
In one aspect, the invention encompasses a method of forming a container-shaped physical vapor deposition target. A conductive material is provided in a container-shape. The container-shape comprises an interior region and an exterior region, and the conductive material comprises an interior surface along the interior region as well as an exterior surface along the exterior region. A sputtering material is electrolytically deposited on at least one of the interior and exterior surfaces of the container-shaped conductive material.
In another aspect, the invention encompasses a container-shaped physical vapor deposition target. The target includes a first conductive material in a container-shape, with the container-shape comprising an interior region and an exterior region. The first conductive material comprises an interior surface along the interior region of the container-shape and an exterior surface along the exterior region of the container shape. The physical vapor deposition target further includes a second conductive material on an entirety of at least one of the interior and exterior surfaces of the first conductive material, with the second conductive material having at least one different metallurgical property than the first conductive material.